Autopsy - The Sleuth Kit - Autopsy is an open source graphical interface to The Sleuth Kit and other digital forensics tools.
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
Encase eDiscovery - EnCase eDiscovery helps litigation experts to establish best practices throughout the e-discovery workflow.
Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.
Forensic Toolkit FTK - Digital Investigations
Windows BitLocker - This topic provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.